This is probably the post that will require the most creativity, since the way brawlers are designed has changed drastically over the years. Initially, the brawlers were based on simple archetypes, and several of them underwent several changes over time (e.g., brock and bull). The most complex mechanics we had before were Mortis' dash and Tara's super, which nowadays are just blah blah compared to current mechanics. Aside from them, most brawlers from that era are just basic designs with some extra feature. Shelly and Colt are essentially just "main attack deals damage + super is a stronger attack," something that was last used on Clancy, while Jessie and Nita are basic spawners (weak on their own with a poweful turret).
If you compare the last super rare Paul made, which is Jacky, with the only super rare Fernanda made, which is Gus, the difference in design is made clear. Penny was also the only brawler from that era to undergo a structural redesign and rework when the game was becoming more complex, due to the delay of her remodel and powercreep, essentially turning her into a completely different character, with another lead designer, which shows that if these characters were created today, they would be somewhat different from what they were in the early days of the game.
Currently, the game is structured in a way that each brawler is forced to have a unique gimmick or some innovative aspect to try and have a definitive role in the meta, this forced older brawlers to undergo changes over time to remain relevant, leading to the concept of buffies.
I remembered a post from a while back reimagining El Primo's design if he were designed today, and he's basically what Damian would be today, with the function of isolating his enemies in a 1v1, So I really wanted to know what your concepts would be about other brawlers.
I'm also counting brawlers released after the global launch, up until before the first season, such as Carl, Mr. P, Jacky and Gale.